Ifanelekile kubantu abathanda ukulala ngecala elinye, bane-vertebra yomlomo wesibeleko kunye neentlungu zegxalaba, basebenze ngefowuni ephathekayo okanye intloko phantsi ixesha elide, kwaye bahlala bebila kwaye besaba ukushisa.Xa ulele ngasemva, umbindi we-butterfly design ye-3D, i-radian ukuxhasa intloko, intamo kunye nehlombe, ukulala kwentamo yokukhusela.Xa ulala ngecala, idizayini ekhethekileyo yephiko le-occipital elenga i-degrees ezingama-45 ikhupha uxinzelelo lwentamo ukwenzela ukuba ihlombe lixhaswe ngokupheleleyo.